This invention relates to a tamper-evident lid to be used with a container such that upon removal of the lid from the container, the fact of such removal is visually indicated. The present invention provides a closure cap which will automatically provide an indication of attempts to open the container and attempts to replace the container with a different container. This invention has particular utility in the container industry to prevent consumers from being injured by contaminated products which are inserted in containers after the manufacturing and packaging processes.
There are a number of various types of tamper-evident container lids which are known. One type of container lid contains a dye in capsules which are ruptured upon turning the lid. This is illustrated by U.S. Pat. No. 4,519,515 to Schonberger.
Another type of container lid is shown in U.S. Pat. No. 3,073,468 to Arneson which describes a mechanical type tamper-evident closure lid. In this device, once the closure cap is turned to open the closure lid, the device indicates that a attempt has been made to rotate the lid in this opening direction. All of these known mechanical type lid assemblies, however, only provide an indication that a closure lid has been rotated in the container opening direction.
A major disadvantage of the mechanical type closures such as illustrated in the Arneson reference is that no indication of tampering is provided when the container is broken away from the closure cap and a new container, possibly with a contaminated product, is inserted in place of the original container.